The Petri MF-2 is an analog 35mm single-lens reflex (SLR) camera. It was manufactured by the Cosina company for the Petri brand. In terms of functionality, the model is similar to the Cosina CSM. The camera was sold in the 1970s.
Lens
The Petri MF-2 uses the widely used M42 screw mount. This universal mount allows the use of a wide range of lenses from manufacturers such as Pentax, Zeiss, Zenit, and many others, giving the photographer great flexibility in choosing focal length and aperture.
Focusing is done entirely manually using the focusing ring on the lens. To assist with precise focusing, the camera's viewfinder is equipped with a focusing aid. This consists of a central horizontal split-image indicator surrounded by a microprism ring.
A subject is considered in focus when the two halves of the split image exactly meet and the image in the microprism ring appears clear and flicker-free.
The camera does not have an autofocus function. The lenses also have a depth-of-field scale, which, in conjunction with the aperture setting, indicates which distance range in front of and behind the focused point is in focus.
Exposure Settings
The Petri MF-2's exposure metering is performed through the lens (TTL) using a "stop-down" metering method. Two sensitive cadmium sulfide (CdS) cells, positioned next to the eyepiece, measure the light center-weighted across the entire image area.
To take a metering, the photographer must press the shutter button halfway. This closes the lens aperture to the preset value and simultaneously activates the light meter.
The camera has no automatic exposure modes; aperture and shutter speed must be set manually.
Exposure information is displayed in the viewfinder via three LEDs: A red plus symbol (+) indicates overexposure, a red minus symbol (-) indicates underexposure. If the green "OK" LED in the center lights up, the exposure is correct within a tolerance of 0.3 EV. The photographer then adjusts either the aperture on the lens ring or the shutter speed on the control dial until the green LED lights up.
The shutter is an electronically controlled cloth focal plane shutter. It offers shutter speeds from 4 seconds to 1/1000 second, as well as a "B" setting (Bulb) for long exposures.
A special feature is the purely mechanical shutter speed of 1/50 second, which also works without battery power. The film speed is set manually on the outer ring of the shutter speed dial and ranges from ASA 25 to 3200.
Flash System
For flash photography, the Petri MF-2 is equipped with a central hot shoe with a center contact. This allows for the direct attachment of wireless electronic flash units.
Flash synchronization is guaranteed at shutter speeds up to 1/60 second. This synchronization speed is marked in red on the shutter speed dial for easier identification.
In addition to the hot shoe, the camera features a side "X" sync connector (PC socket) that allows the connection of external flash units via cable.
Additional Features
The Petri MF-2 offers several useful additional features.
A mechanical self-timer delays the shutter release by approximately 10 seconds. During the countdown, a red indicator light on the front of the camera flashes. This feature is ideal for self-portraits or to minimize camera shake during long exposures.
For stable shots, the camera can be mounted on the bottom using the standard tripod thread.
An important feature for working with the stop-down metering system is the aperture release button. After selecting a small aperture (high f-number), the viewfinder image becomes dark during metering. Pressing this button fully opens the aperture, allowing for a bright viewfinder image for easier focusing and composition before the actual shot is taken.
A film counter displays the number of frames already exposed and automatically resets to "S" (Start) when the back is opened.
Dimensions and Weight
The Petri MF-2's camera body is compact and robustly built. The dimensions of the body are 136.5 mm wide, 83.2 mm high, and 51 mm deep. The weight of the camera body without lens is 540 grams.
Power Supply
To operate the electronically controlled shutter and the LED light meter, the Petri MF-2 requires two 1.5-volt silver oxide batteries of the type S-76 (eBay / Amazon*)
Modern equivalents such as LR44 (eBay / Amazon*) or SR44 (eBay / Amazon*) are also compatible. The batteries are inserted into a compartment on the bottom of the camera.
A simple battery test is possible by half-pressing the shutter button: If one of the LEDs in the viewfinder lights up, the power supply is sufficient. The exception is the mechanical shutter speed of 1/50 s, which works even when batteries are empty or missing, thus ensuring the camera's basic operational readiness.
Film Recommendations
The camera uses standard 35mm film.
Since the film speed must be set manually (the camera does not have DX code recognition), it is compatible with virtually any film type available on the market. The adjustable range of ASA 25 to 3200 covers all common applications.
The film format continues to offer a diverse range of material for color and black-and-white images. For color shots, you can use the Kodak Portra 400* . The Kodak T-Max 100* is recommended for black-and-white images.
Quick Operation Guide
Operating the Petri MF-2 is straightforward. First, insert the batteries and load the 35mm film. The film speed (ASA/ISO) is then set by lifting and turning the ring on the shutter speed dial.
The photographer then selects the desired combination of lens aperture and camera shutter speed. While looking through the viewfinder, the subject is focused using the split-image indicator and the microprism ring. Pressing the shutter button halfway activates the exposure meter. The aperture or shutter speed is adjusted until the green "OK" LED in the viewfinder lights up. The shutter button is then pressed fully to take the photo.
The film advance lever advances to the next frame. After the last frame, the film is rewound into the cartridge by pressing the rewind button on the bottom and turning the rewind crank.
